This invention relates to alkyl-substituted thiapolycyclic polyahls which have utility as monomers in making polyamides and other polymers.
A polymer is a large molecule built up by the repetition of small, simpler chemical units called monomers. The character of the monomer unit has a strong effect on the physical and chemical properties of the polymer. For example, it is common to incorporate a para-phenylene group into a monomer to add rigidity to the polymer chain. This can engender desirable properties in the polymer such as: raising the melting point, increasing the stress-strain property ratios and improving the heat distortion performance.
The incorporation of aromatic nuclei in polymer chains, however, has its drawbacks. Polymers containing aromatic nuclei are susceptible to deterioration. They may stiffen and become brittle, change color, or yellow and weaken. Opaque fillers and light stabilizers and antioxidants are added to alleviate these problems. Aliphatic monomers yield polymers which are less susceptible to degradation but do not impart the same rigidity.
In view of the aforementioned deficiencies of both aliphatic and aromatic polymers, it would be highly desirable to provide a monomer which can form a polymer having ridigity, strength and thermal properties characteristic of aromatic polymers and resistance to degradation by light that is characteristic of aliphatic polymers.